title: Photorefractive keratectomy in patients with mild to moderate stable keratoconus: a five-year prospective follow-up study.
abstract: BACKGROUND
  The purpose of this study was to evaluate the visual outcome of photorefractive keratectomy (PRK) in patients with mild to moderate stable keratoconus and to assess the risk of progression of the disease after the excimer laser procedure.
  
  
  METHODS
  In this prospective study, carried out at the Clemenceau Medical Center, an affiliate of Johns Hopkins International, in Beirut, Lebanon, 119 eyes from 72 patients with grade 1-2 keratoconus (Amsler-Krumeich classification) underwent PRK. Forty-seven patients had both eyes treated and 25 patients had one eye treated. The procedure was done using the Wavelight Eye Q Excimer laser. Uncorrected and best-corrected visual acuity, corneal topography, and pachymetry were assessed before the procedure and 3, 6, 12, 36, and 60 months after the procedure.
  
  
  RESULTS
  Mean uncorrected visual acuity showed a statistically significant improvement (P < 0.05) at one, 3, and 5 years follow-up. One hundred and seventeen eyes (98.3%) showed no progression while two eyes (1.7%) showed progression of the disease at 5 years follow-up, as documented by corneal topography and pachymetry. These two eyes were treated with corneal collagen crosslinking.
  
  
  CONCLUSIONS
  PRK in mild to moderate keratoconus is a safe and effective procedure for improving uncorrected vision in patients with mild refractive errors. However, close follow-up of patients is needed to detect any progression of the disease. Longer follow-up is needed to assess the overall effect of this procedure on progression of the disease.
authors.affiliation: Saint-Joseph University, Faculty of Medicine, Beirut, Lebanon.
authors.forename: Elias
authors.initials: E
authors.lastname: Chelala
authors.forename: Hala El
authors.initials: HE
authors.lastname: Rami
authors.forename: Ali
authors.initials: A
authors.lastname: Dirani
authors.forename: Ali
authors.initials: A
authors.lastname: Fadlallah
authors.forename: Omar
authors.initials: O
authors.lastname: Fakhoury
authors.forename: Elias
authors.initials: E
authors.lastname: Warrak
keywords: photorefractive keratectomy; stable keratoconus